The Osborne 1

The Osborne 1 was the first commercially successful portable microcomputer, released on April 3, 1981 by Osborne Computer Corporation.

It weighed 10.7 kg (23.5 lb), cost $1,795 (USD), and ran the then-popular CP/M 2.2 operating system. The computer shipped with a large bundle of software that was almost equivalent in value to the machine itself, a practice adopted by other CP/M computer vendors.

Its principal deficiencies were a tiny 5-inch (13 cm) display screen and use of single sided, single density floppy disk drives which could not contain sufficient data for practical business applications, and considerable unit weight. The Osborne’s market was quickly filled with competitors such as the Kaypro II that used double sided drives and larger 9″ screens that could hold a full 80×25 display.